JPH10110390A - Polyester fiber for reinforcing ethylene-propylene rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polyester fibers suitable for reinforcing ethylene-propylene rubber by forming a covering film of a second treating agent containing a chlorophenol-resorcinol-formalin cocondensed material, etc., on a covering film of a first treating agent containing polyepoxide, etc. SOLUTION: This reinforcing fiber is obtained by applying a first treating agent solution containing a polyepoxide compound such as a polyglycidyl ether of a polyhydric alcohol and rubber latex such as a vinylpyridine-styrene- butadiene terpolymer onto polyester fibers to form a covering film of the first treating agent on the surface of the fibers, then covering the covering film of the first treating agent with a covering film of a second treating agent containing a chlorophenol-resorcinol-formalin cocondensed material containing resorcinol-formalin-rubber latex, an oxazoline group-containing compound and a compound expressed by formulae I, II and III as principal components and having 20wt.% of solid concentration and 70-150 centipoise viscosity of an alkaline aqueous solution having pH at 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyester fiber for a rubber composite. More specifically, it has good adhesion to ethylene propylene rubber, for example, rubber hose,
The present invention relates to an ethylene propylene-based rubber reinforcing polyester fiber suitable for a fiber reinforcing layer such as a V belt or a conveyor belt or a fiber base fabric.

[0002]

2. Description of the Related Art Polyester fibers represented by polyethylene terephthalate fibers have physical properties such as high strength and Young's modulus, low elongation, low creep and excellent fatigue properties. It is widely used for applications such as reinforced composites. On the other hand, in the field of hoses and belts, rubber materials have been changing to have excellent high-temperature characteristics, for example, due to a rise in the temperature of an engine room of an automobile. As one of them, there is an ethylene propylene rubber. However, since the rubber has little double bond in chemical structure and poor reactivity, it is difficult to bond reinforcing fibers with the conventional method, and a satisfactory adhesive strength is obtained. It is very difficult at present. That is, when a polyester fiber is applied to reinforce an ethylene-propylene rubber, the fiber surface is relatively inactive, so that the adhesiveness with the low-reactivity rubber matrix was insufficient.

In order to solve such a problem, there have been proposed methods of treating polyester fibers with various treating agents. For example, "Resorcinol-formaldehyde latex (RF using polybutadiene latex and styrene-butadiene-vinylpyridine copolymer latex on polyester fiber provided with epoxy compound)
L) Ethylene propylene-based rubber reinforcing polyester fiber treated with an adhesive liquid containing an ethylene urea compound added to L)
(JP-A-60-219243), "Resorcinol-formaldehyde latex (RFL) blended with blocked polyisocyanate compound and parachlorophenol-resorcinol-formalin co-condensate ethylene into polyester fiber provided with epoxy compound Ethylene propylene rubber reinforcing polyester fiber treated with the prepared adhesive liquid "(Japanese Patent Application Laid-Open No. Hei 7-331584)," Polyester fiber provided with rubber latex containing epoxy compound, resorcinol-formaldehyde rubber latex (RFL) " Polyethylene Fiber for Reinforcing Ethylene Propylene Rubber Treated with Adhesive Liquid Containing Blocked Polyisocyanate Compound and Parachlorophenol / Resorcin / Formalin Cocondensate ”(JP-A-7-21)
No. 6755) has been proposed. However,
At present, even with these techniques, the adhesiveness to ethylene propylene rubber has not reached a sufficient level.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyester fiber having improved adhesion with an ethylene propylene rubber matrix. To provide.

[0005]

Means for Solving the Problems The object of the present invention is to provide:
"Polyester fibers are coated with a first treating agent coating comprising a polyepoxide compound and a rubber latex,
Resorcinol, formalin, rubber latex (RFL),
Compound having oxazoline group and chlorophenol
This is achieved by an ethylene propylene-based rubber reinforcing polyester fiber coated with a second treating agent film containing a resorcinol-formalin cocondensate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester fiber referred to in the present invention is a fiber comprising a polymer composed of an aromatic dicarboxylic acid component and a glycol component. In particular, ethylene glycol or tetramethylene glycol is used as a glycol component, and terephthalic acid is used. Polyester fibers containing an acid or naphthalenedicarboxylic acid as a main acid component are preferred. Single yarn fineness of polyester fiber, number of filaments, cross-sectional shape,
Fiber properties, microstructure, presence or absence of additives, and polymer properties (average molecular weight, terminal carboxyl group concentration, etc.) are arbitrary and need not be particularly limited.

The polyepoxide compound used in the first treating agent of the present invention is a compound containing at least two or more epoxy groups per molecule in an amount of 0.2 g equivalent or more per 100 g of the compound, such as ethylene glycol and glycerol. Reaction products of polyhydric alcohols such as sorbitol, pentaerythritol and polyethylene glycol with halogen-containing epoxides such as epichlorohydrin, resorcin / bis (4-hydroxyphenyl) dimethylmethane, phenol / formaldehyde resin, resorcin / formaldehyde resin, etc. Reaction products of the above-mentioned polyhydric phenols with the above-mentioned halogen-containing epoxides, and polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide. Specific examples include 3,4-epoxycyclohexene epoxide,
4-epoxycyclohexenemethyl-3,4-epoxycyclohexenecarboxylate, bis (3,4-epoxy-6-methyl-cyclohexylmethyl) adipate and the like can be mentioned. Among them, a reaction product of a polyhydric alcohol and epichlorohydrin, that is, a polyglycidyl ether compound of a polyhydric alcohol is particularly preferred because it exhibits excellent performance.

[0008] Such a polyepoxide compound is usually used as an emulsion. In order to prepare an emulsion or a solution, for example, such a polyepoxide compound as it is, or a solution obtained by dissolving it in a small amount of a solvent as necessary, a known emulsifier,
For example, emulsification or dissolution is carried out using sodium alkylbenzene sulfonate, dioctyl sulfosuccinate sodium salt, nonylphenol ethylene oxide adduct, or the like.

The rubber latex used in the first treating agent includes, for example, natural rubber latex, styrene / butadiene copolymer rubber latex, vinyl pyridine /
There are styrene-butadiene terpolymer latex and the like, and these are used alone or in combination. Among these, excellent performance is obtained when vinyl pyridine / styrene / butadiene terpolymer latex is used alone or 以上 or more.

The first treating agent comprises the above-mentioned polyepoxide compound and rubber latex, and the compounding ratio does not need to be particularly limited. Usually, 0.5 to 2.0 parts by weight of a rubber latex (active ingredient) is blended with respect to 1 part by weight of the polyepoxide compound, and the concentration of the polyepoxide compound in the treating agent is 3% by weight or less, preferably 0.5 to 2.0%. 2.0% by weight is preferred from the viewpoint of handleability. The amount of the first treatment agent attached is
1 to 8% by weight, preferably 3 to 5% by weight based on fiber weight
Is appropriate. If the amount of the first treatment agent is less than 1% by weight, the effect of improving the adhesiveness of the polyepoxide compound is not sufficiently exhibited. Tends to decrease.

The RFL used for the second treating agent is a mixture of an initial condensate (RF) and a rubber latex obtained by reacting resorcinol and formalin in the presence of an alkali or acidic catalyst. Regarding the mixing ratio of the rubber latex and any of the known techniques, the effect can be obtained. Usually, the molar ratio of resorcin to formalin is from 1: 0.1 to 1: 8, preferably from 1: 0.5 to 1: 5. The amount of RF varies depending on the amount of a compound having an oxazoline group and a chlorophenol / resorcin / formalin co-condensate (hereinafter sometimes simply referred to as a chlorophenol compound), which is usually expressed in a solid content ratio. , 1: 1 to 1: 1
5, preferably 1: 3 to 1:12. If the compounding ratio of the rubber latex is too small, the polyester fiber after the treatment becomes hard and the fatigue resistance tends to decrease, and if it is too large, the adhesive performance tends to decrease. The rubber latex used here is the same as the rubber latex used in the above-mentioned first treatment agent, for example, natural rubber latex, polybutadiene latex, styrene.
There are a butadiene copolymer rubber latex and a vinylpyridine / styrene / butadiene terpolymer latex, and these are used alone or in combination. Among these, excellent performance is exhibited when vinylpyridine / styrene / butadiene terpolymer latex or polybutadiene latex is used alone or in combination, particularly when used in a ratio of 7: 3 to 3: 7.

The compound having an oxazoline group in the molecular structure compounded in the above-mentioned RFL refers to an ordinary low molecular weight organic compound or an oxazoline group (preferably an organic polymer or oligomer) having a main skeleton at the terminal or side chain. 2-
Oxazoline group). The number of oxazoline groups may be one or two or more in the molecule. However, in order to improve the adhesive performance, the number of oxazoline groups which are reactive functional groups is increased. It is preferable to do it. Examples of the molecular skeleton having an oxazoline group bonded thereto include hydrocarbon chains, ethylene glycol chains, bisphenols such as bisphenol A, and phenols such as phenolic resins, novolak resins, and resol resins, and formalin initial condensates. A substance containing an aromatic ring or a hetero ring in the skeleton is also used. Further, a compound containing an oxazoline group at a terminal or a side chain of a main component monomer and / or a polymer or oligomer comprising the same is also useful. These monomers include styrene, styrene derivatives,
Acrylonitrile, methacrylic acid ester, methacrylic acid, acrylic acid ester, acrylic acid, ethylene, butadiene, acrylamide and the like are used, and these are used as a single polymer and / or oligomer and further as a copolymer. Further, it can be used as a mixture of these polymers or oligomers.

The compound having an oxazoline group may be in the form of a liquid, a melt, a solid, or a solution or dispersion of these in water or an organic solvent (emulsion particles, latex particles, etc.). ) May be used. For example, such a compound as it is or dissolved in a small amount of a solvent as necessary is emulsified or dissolved using a known emulsifier, for example, sodium alkylbenzene sulfonate, dioctyl sulfosuccinate sodium salt, nonylphenol ethylene oxide adduct or the like. May be used.

The chlorophenol / resorcin / formalin cocondensate used in the second treating agent is a compound obtained by cocondensing chlorophenols, preferably parachlorophenol and resorcin with formaldehyde,
Above all, those containing as a main component trinuclear (I), pentanuclear (II), and heptanuclear (III) compounds represented by the following structural formula (Chemical Formula 2) are preferable, and the solid content concentration is particularly 20% by weight. %, PH1
The viscosity of the alkaline aqueous solution of 0 is in the range of 70 to 150 centipoise, for example, the molecular weight distribution as shown in FIG. Preferred (a solid content obtained by evaporating the co-condensation product to dryness is dissolved in tetrahydrofuran, and this is measured by a GPC method according to a conventional method).

[0015]

Embedded image

The second treating agent of the present invention comprises a compound having an oxazoline group in the RFL and parachlorophenol.
A compound containing a resorcinol-formalin cocondensate, but the compound having an oxazoline group is RFL
0.5 to 30% by weight based on the solid content, preferably 1.0%
A range of -20% by weight is suitable. When the amount is too small, the adhesive performance tends to decrease, and it becomes difficult to obtain a sufficient adhesive strength and rubber adhesion rate. Conversely, if the amount of addition increases, the viscosity of the processing agent increases significantly, making the processing operation of the fiber material difficult, and the effect of merely increasing the compounding amount because the adhesive strength and the rubber adhesion rate reach saturation values. In addition, the fiber material after treatment is extremely hard and its strength is apt to decrease. On the other hand, the solid content ratio of RFL and chlorophenol / resorcin / formalin cocondensate varies depending on the content of the rubber to be adhered, but the former / the latter is usually 50 / 50-80.
/ 20 (weight ratio) is appropriate.

It is preferable to further add a blocked polyisocyanate compound to the second treating agent of the present invention in addition to the above, since the adhesive performance (adhesive strength, rubber adhesion rate, etc.) is improved. Here, the blocked polyisocyanate compound is an addition reaction product of the polyisocyanate compound and the blocking agent, and is a compound that releases a blocking component by heating to generate an active polyisocyanate compound. Examples of the polyisocyanate compound include polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, and triphenylmethane triisocyanate, or those polyisocyanates and two or more active hydrogen atoms. A compound having an isocyanate group (-NCO) and a hydroxyl group (-O
Aromatic polyisocyanates such as polyalkylene glycol adduct polyisocyanate having terminal isocyanate groups and polymethylene polyphenyl isocyanate obtained by reacting at a molar ratio of H) exceeding 1 are preferred because they exhibit excellent performance.

As the blocking agent, for example, phenol,
Thiophenols, cresols, phenols such as resorcinol, diphenylamines, aromatic secondary amines such as xylidine, phthalic imides, caprolactam, lactams such as valerolactam, oximes such as acetoxime, methyl ethyl ketoxime, cyclohexanone oxime and There are sodium acid sulfite and the like.

The compounding amount of the blocked polyisocyanate compound is not constant depending on the kind of the compound and the compounding of the rubber to be coated.
Preferably, 10 to 30% by weight is appropriate.

The above-mentioned second treating agent usually has a solid content of 10 to 10.
It is adjusted to contain 25% by weight, preferably 15 to 20% by weight. The amount of the second treating agent to be applied is appropriately in the range of 1 to 10% by weight, preferably 2 to 7% by weight based on the weight of the fiber. If the amount of the second treating agent is less than 1% by weight, the effect of bonding to the ethylene-propylene rubber is not sufficiently exhibited, while if it exceeds 10% by weight, the adhesive performance tends to be deteriorated.

In order to attach the first and second treating agents to the polyester fiber, an arbitrary method such as applying through a roller, applying by spraying from a nozzle, immersing in a treating solution, or the like is adopted. Can be. In order to adjust the amount of solids attached to the fiber, squeezing with a pressing roller, scraping off with a scrubber, blowing off with air blowing,
Means such as suctioning and knocking down with a beater may be used.

The polyester fiber to which the first treatment agent has been applied is dried and heat-treated at a temperature of 50 ° C. or more and lower than the melting point of the polyester fiber by at least 10 ° C., preferably at a temperature of 180 to 250 ° C., and then the second treatment agent is applied. And a temperature of at least 120 ° C. and at least 10 ° C. lower than the melting point of the polyester fiber,
Drying and heat treatment are preferably performed at a temperature of 180 to 250 ° C. If the heat treatment temperature is too low, adhesion to rubbers tends to be insufficient, while if the temperature is too high, the polyester fibers are melted / fused or cause strong deterioration, making it difficult to be put to practical use.

[0023]

The present invention will be described below in detail with reference to examples. Note that the cord peeling adhesive strength and T adhesive strength in the examples are values obtained as follows. The flexural hardness of the cord was measured by the Gurley method, and the larger the measured value, the harder the cord.

<Cord Peeling Adhesion> This shows the adhesion between the treated cord and the rubber. Twenty-five polyester treatment cords are arranged in one inch, embedded in ethylene propylene unvulcanized rubber, and vulcanized at 150 ° C. for 30 minutes under pressure.
The force required to separate the cord and rubber from the rubber sheet at a speed of 200 mm / min is shown in kg / inch.

<T Adhesion> This shows the adhesion between the treatment cord and the rubber. The treatment cord was embedded in a rubber block, vulcanized at 150 ° C. for 30 minutes under pressure, and then pulled out from the rubber block at a speed of 200 mm / min. The force required for pulling was indicated in kg / cm.

Example 1 A multifilament (1) made of polyethylene terephthalate having an intrinsic viscosity of 0.90
(500 denier / 250 filaments) was twisted 10 times per 10 cm to form a cord, which was then treated by a dipping machine using the following first treating agent.

Polyepoxide compound (Denacol Ex-
314, manufactured by Nagase Kasei Co., Ltd., 50 g of polyglycidyl ether), Neocol SW-30 (dioctyl sulfosuccinate sodium salt, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
5 g (solid content: 30% by weight) was dispersed in 815 g of water, and then 125 g (solid content: 30% by weight) of vinyl pyridine / styrene / butadiene terpolymer latex (Nippol 2518GL, manufactured by Zeon Corporation) ) Is mixed and stirred, and 3 is added as an epoxy curing agent.
5 g of boron fluoride monoethylamine complex salt (manufactured by Hashimoto Kasei Kogyo Co., Ltd.) was added and adjusted to obtain a first treating agent.

After immersing the cord in the first treatment liquid,
After drying at ~ 150 ° C for 1-3 minutes, 130 ~ 200
A heat treatment was performed at a temperature of 1 to 3 minutes. The attached amount of the first treating agent was 3.5% by weight based on the cord weight. Next, it processed using the following 2nd processing agents.

17 g of resorcinol and 14.9 g of 37% formalin aqueous solution were added with 13.3 g of caustic soda.
The reaction was performed in 3.5 g of water to obtain an RF resin. Next, vinyl pyridine / styrene / butadiene 3 was added to this RF resin.
187.5 g of a copolymerized latex (Nippol 2518GL, manufactured by Zeon Corporation, solid content 40%) and polybutadiene rubber latex (Nippol Lx-111)
NF, manufactured by Zeon Corporation, solid content 55%) 27
2.7 g (RF / L mixture weight ratio = 10/1), and further elastron BN-69 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., water-soluble blocked polyisocyanate compound 40%)
62.0 g of an aqueous solution, a compound having an oxazoline group (Epocross K-2030E, manufactured by Nippon Shokubai Co., Ltd., styrene butyl acrylate 2-isopropenyl-2)
62 g of an oxazoline / divinylbenzene copolymer (40% aqueous solution) is added and mixed (RFL / oxazoline-containing compound mixture weight ratio = 9.5 / 0.5), and then aged at room temperature for 24 hours. Immediately before use, 450 g of parachlorophenol / resorcin / formalin cocondensate (Denabond E, manufactured by Nagase Kasei Co., Ltd., solid content 20%) was added (RFL / chlorophenol compound mixture weight ratio = 73/27), Use with good stirring.

After the cord treated with the first treating agent is immersed in the above-mentioned second treating agent solution, it is dried at 130 to 170 ° C. for 1 to 3 minutes, and then heat-treated at 180 to 240 ° C. for 1 to 3 minutes. Was. The attached amount of the second treatment agent was 3% by weight based on the cord weight. The amount of the first treatment agent and the amount of the second treatment agent were controlled by adjusting the pressure of air that blows off the liquid after the addition of water to the treatment agent or the immersion treatment.

The obtained adhesive treatment cord was measured for flexural hardness, embedded in ethylene propylene unvulcanized rubber having the composition shown in the following table, and subjected to press vulcanization at 150 ° C. for 30 minutes for peel adhesion. And the pull-out adhesive strength was measured. The compounding composition of the rubber used for the evaluation is as follows. Table 1 shows the results. EPDM 100 parts HAF-carbon black 120 parts Process oil (porafine) 90 parts Zinc white 5 parts Stearic acid 3 parts Vulcanizing agent 3.5 parts Vulcanization accelerator 2.5 parts

Examples 2 to 6, Comparative Examples 1 to 4
In the same manner as in Example 1, except that the presence or absence of the first treatment agent and the amounts of the oxazoline compound and the chlorophenol compound in the second treatment agent were changed. The results are shown in Table 1.

[0033]

[Table 1]

[0034]

The polyester fiber for reinforcing ethylene propylene rubber of the present invention is first coated with a first treating agent coating containing an epoxy group, and then has an excellent affinity with the ethylene propylene rubber for the rubber adhered to the RFL. Is coated with a parachlorophenol / resorcin / formalin cocondensate and a compound having a highly reactive oxazoline group. The bond with the film (adhesive layer) is made strong, and the second treatment agent film has an RFL
Along with the rubber latex inside, parachlorophenol
The resorcinol-formalin co-condensate promotes the compatibility of the first treatment agent coating and the rubber to be applied with the ethylene propylene rubber, and the compound having an oxazoline group enhances the cohesive force of the second treatment agent coating. As a result, excellent adhesive properties and heat resistance thereof can be obtained while sufficiently exhibiting the excellent properties inherent to polyester fibers as the ethylene propylene rubber reinforcing fibers.

[Brief description of the drawings]

FIG. 1 is an example of a preferable molecular weight distribution of parachlorophenol / resorcin / formalin cocondensate used in the present invention.

Claims (2)

[Claims] A polyester fiber is coated with a first treating agent coating containing a polyepoxide compound and a rubber latex, and then resorcinol-formalin rubber latex (RFL), a compound having an oxazoline group and chlorophenol-resorcinol-formalin A polyester fiber for reinforcing an ethylene-propylene-based rubber, which is coated with a second treating agent film containing a co-condensate. 2. The chlorophenol / resorcin / formalin cocondensate comprises a trinuclear (I), a pentanuclear (II) and a heptanuclear (II) represented by the following formula (1) as a main component. The polyester fiber for reinforcing ethylene propylene rubber according to claim 1, wherein the solid content concentration is 20% by weight, and the viscosity of the alkaline aqueous solution of PH10 is 70 to 150 centipoise. Embedded image